Technical Field
The present invention relates to an adsorption characteristic measuring apparatus and more particularly to an adsorption characteristic measuring apparatus for obtaining an adsorption isotherm using a constant volume method.
Related Art
As a method of evaluating a pore distribution in a material or a specific surface area of the material, a gas adsorption method is used. For example, an adsorption characteristic measuring apparatus, which measures an adsorption isotherm using a constant volume method to evaluate a specific surface area or a pore distribution, includes a plurality of pressure gauges, valves such as on-off valves, and a vacuum exhaust system to supply an adsorption gas having a predetermined number of moles to a sample in the sample tube, which is set to constant volume and temperature, and to measure the pressure change before and after adsorption.
JP 2014-81250 A discloses an example where a powder sample is accommodated in a sample tube made of glass, a nitrogen gas is used as an adsorption gas, the sample tube is disposed in a Dewar vessel filled with liquid nitrogen, and a pressure change in the sample tube is measured under a constant liquid nitrogen temperature of 77K.